2007 Mazda BT 50 2.5 liter diesel manual wont start but fires up with arostart and runs perfectly have tested glow plugs and replaced crank sensor it dosent matter hot or cold it wont start without arostart but then will run faultlessly all day.
Because while cranking it if I hit it with arestart it will start I though glow plugs, So after testing the glow plugs I hot wired them directly with 12 volts and held them for 20 seconds and while cranking but still no go so I figger it cant be the glow plugs. I then went for the fuel but if i squirt it with arostart it starts and then runs perfectly at all reves , it will run all day without fault, So I tried replacing the crank sensor and that made no difference whatsoever. This thing is driving me crazy I just cant figger out what the fault can be. It sorta points to fuel but once it fires there is no fuel problem whatsoever.I have checked fuel lines and filters ect. We have tried anouther starter that we new works although the original is spinning it over very well. Compression is OK as I say it runs fine once started. I am now at my wits end with it. Has anyone any idea where I can look next.

 

Common problem with electromagnetic interference from the starter motor upsetting either the crank or cam sensor. You need to scope both sensors to check/inspect clean clear signal to the PCM or view live data for RPM on cranking ( will show an erratic RPM signal )

New starter motor is the fix, if it is the case.

 

I have the same car with the same problem as described above.
Does anyone have a solution for this problem?
I’m verry grateful if someone can give me any tips.

 

Have you scoped the cam & crank sensors? Do you have a clean signal?

 

I have a 2009 3.0 litre and it has the same issue, struggle start morning and afternoon after I finish work.

 

Same issue 2007 mazda bt 50
The longer I drive it the harder it is to start
but will still take a extra extra crank or two in the morning
I must resolve this issue

 

Howdy
I have a BT50 2010 model, 3 litre diesel.100000km.
Started the Journey 3 years ago.
starting issue got worst gradually, had to turn it over for a while to get it to start.
Replaced fuel filter, injectors serviced, glow plugs replaced and new optima 975 CCA battery.
not much changed.
Then eventually would not start.
Mazda investigate and said it needs a new crank angle sensor, replaced crank angle sensor with no success.
Then said ECU needs replacing, quote $4000? Stop there.
Sent it to a diesel performance place, they replaced the starter motor and was good for 13 months and same related issue.12 months out of warranty and refund on repair cost.
Tried another mechanic and he found out the starter motor should be a upgraded model to stop the electromagnetic issue causing the crank angle sensor fault.
Fitted a new starter motor and 12 months down the track same issue again.
The mechanic fitted another heavy duty starter motor that I should not have any issues with.
And now again 12 months down the track having troubles starting.
The engine is cranking well and good battery voltage.
Any tips would be great before going back to the mechanic again.
Also I purchased OBD11 reading and P0335 crank angle sensor fault is coming up again.

 

I have a Mazda BT50 3.0 ltr turbo diesel. Very hard to start. Once it is running it runs perfect. If you crank for to long it comes up with crank angle sensor fault. Repced it and it made no difference. Replaced faulty starter motor and it started good for a few days. Now it is back to how it was before. Have replaced glow plugs. Swapped fuel filter housing and primer. Has anyone out there got any suggestions.
cheers Ross

 

CRDI engines have a fuel rail pressure sensor that prevents starting if the fuel pressure is too low. This should be visable with a good scantool when cranking by looking at live data. Apart from that the most important thing with any diesel is good compression.